1. Vertical Mill Operations
Unit 62

2. Objectives
Align the vertical head and vise to within ±.001 in. (0.02 mm)
Insert and remove end mills from spring collets
Accurately machine a block square and parallel
Drill holes to an accurate location

3. Vertical Milling Machine
Versatile and easy setup
Performs wide variety of operations
End milling, face milling
Keyway and dovetail cutting
T-slot and circular slot cutting
Gear cutting, drilling, boring, reaming
Cutting tools used relatively small so cost lower

4. Aligning the Vertical head
Head must be square to table (90º)
Procedure to check spindle alignment
Mount dial indicator on suitable rod, bent at 90º and held in spindle
Position indicator over front Y axis of table
Carefully lower spindle until indicator button touches table and dial indicator registers no more than ¼ revolution; set bezel to zero; Lock spindle in place

5. Carefully rotate spindle 180º by hand until button bears on opposite side of table; Compare readings
If differences, loosen locking nuts on swivel mounting and adjust head until indicator registers approximately ½ difference between two readings; Tighten locking nuts
Recheck accuracy of alignment
Rotate vertical mill spindle 90º and set dial indicator as in step 3

6. Rotate machine spindle 180º, check reading at other end of table
If two readings do not coincide, repeat step 5 until readings are same
Tighten locking nuts on swivel mount
Recheck readings and adjust if necessary

7. Aligning the Vise
When vise aligned on vertical milling machine, dial indicator may be attached to quill or head by clamps or magnetic base
Same method of alignment followed as outlined for aligning vise on horizontal milling machine

8. Collets
Hold end mills, cutting tools and accessories in machine spindle
Spring collet
Pulled into spindle by draw-bar that closes on cutter shank
Driven by means of friction between collet and cutter
Solid collet
More rigid
Pulled into spindle by draw-bar
Driven by setscrews that bear against flats of cutter shank
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

9. To Mount a Cutter in a Spring Collet
Shut off electric power to machine
Place proper cutter, collet, and wrench on piece of masonite, wood, or soft plastic on table
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

10. Clean taper in machine spindle
Place draw-bar into hole in spindle top
Clean taper and keyway on collet
Insert collet into spindle bottom, press up, and turn until keyway aligns with key in spindle
Hold collet up with one hand and with other, thread draw-bar clockwise into collet
Hold cutting tool with cloth and insert it into collet for full length of shank
Tighten draw-bar into collet (clockwise) by hand
Hold spindle brake lever and tighten draw-bar tightly as possible with wrench

11. Procedure to Remove Cutter from a Collet
Operation for removing cutting tools similar to mounting, but in reverse order
Shut off electric power to machine
Place piece of masonite, wood, or soft plastic on machine table to hold necessary tools
Pull on spindle brake lever to lock spindle, loosen draw-bar with wrench (counterclockwise)

12. Loosen draw-bar, by hand, only about three full turns
Hold cutter with cloth
With soft-faced hammer, strike down sharply on head of draw-bar to break taper contact between collet and spindle
Remove cutter from collet
Clean cutter and replace it in its proper storage place where it will not be damaged by other tools

13. To Mount a Cutter in a Solid Collet
Shut off electric power to machine
Place cutter, collet, and necessary tools on piece of masonite, wood, or soft plastic on machine table
Slide draw-bar through top hole in spindle
Clean spindle taper and taper on collet

14. Align keyway or slots of collet with keyway of drive keys in spindle, insert collet into spindle
Hold collet up in spindle and thread draw-bar clockwise with other hand
Pull on brake lever and tighten draw-bar as tightly as possible with wrench
Insert end mill into collet until flat(s) align with setscrew(s) of collet
Tighten setscrews securely using hand pressure only

15. Procedure to Machine a Flat Surface
Clean vise and mount work securely in vise, on parallels if necessary
Check that vertical head square with table
Select cutter that will just overlap edges of work
Set proper spindle speed for size and type of cutter and material being machined; check cutter rotation

16. Tighten quill clamps
Start machine, and adjust table until end of work under edge of cutter
Raise table until work surface just touches cutter. Move work clear of cutter.
Raise table about .030 in. and take trial cut for approximately .250 in.
Move work clear of cutter, stop cutter, measure work
Raise table desired amount; lock knee clamp
Mill surface to size using auto feed

17. Machining a Block Square and Parallel
Important that each side be machined in definite order
Machining Side 1
Clean vise thoroughly and remove all burrs from workpiece, vise and parallels
Set work on parallels in center of vise with largest surface (side 1) facing up

18. Place short paper feelers under each corner between parallels and work
Tighten vise securely
With soft-faced hammer, tap workpiece down until all paper feelers are tight
Mount fly cutter in milling machine spindle
Set machine for proper speed for size of cutter and material to be machined
Start machine and raise table until cutter just touches near right-hand end of side 1

19. Move work clear of cutter
Raise table about .030 in. and machine side 1 using steady feed rate
Take work out of vise and remove all burrs from edges with file
Machining Side 2
Clean vise, work, and parallels thoroughly
Place work on parallels, if necessary, with side 1 against solid jaw and side 2 up

20. Place short paper feelers under each corner between parallels and work
Place round bar between side 4 and movable jaw
Tighten vise securely and tap work down until paper feelers are tight
Follow steps 8 to 11 and machine side 2
Machining Side 3
Clean vise, work, and parallels thoroughly

21. Place side 1 against solid vise jaw, with side 2 resting on parallels if necessary
Push parallel to left so that right edge of work extends about .250 in beyond parallel
Place short paper feelers under each end of corner between parallels and work
Place round bar between side 4 and movable jaw, making sure round bar in center of amount of work held inside vise
Tighten vise securely and tap work down until paper feelers are tight

22. Start machine and raise table until cutter just touches near right-hand end of side 3
Move work clear of cutter and raise table about .010 in.
Take trial cut about .250 in. long, stop machine, and measure width of work
Raise table required amount and machine side 3 to correct width
Remove work and file off all burrs

23. Clean vise, work, and parallels thoroughly
Machining Side 4
Clean vise, work, and parallels thoroughly
Place side 1 down on parallels with side 4 up and tighten vise securely
Round bar not required on side 4
Place short paper feelers under each corner between parallels and work
Tighten vise securely
Tap work down until paper feelers tight
Follow steps 24 to 27 and machine side 4 to correct thickness

24. Machining the Ends Square
Two common methods
Short pieces held vertically in vise and machined with end mill or fly cutter
Long pieces held flat in vise, one end extending past end of vise; end surface cut square with body of end mill
Procedure for Short Work
Set work in center of vise with one end up and tighten vise lightly

25. Hold square down firmly on top of vise jaws and bring blade into light contact with side of work
Tap work until edge aligned with blade of square
Tighten vise securely and recheck squareness of side
Take about .030 in. deep cut and machine end square
Remove burrs from end of machined surface

26. Clean vise and set machined end on paper feelers in bottom of vise
Tighten vise securely and tap work down until paper feelers are tight
Take trial cut from end until surface cleans up
Measure length of workpiece with depth micrometer
Raise table required amount and machine work to length

27. Procedure to Machine an Angular Surface
Lay out angular surface
Clean vise
Align vise with direction of feed
Utmost importance
Mount work on parallels in the vise
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

28. Swivel vertical head to required angle Tighten quill clamp
Start machine and raise table until cutter touches work
Raise table until cut desired depth
Take trial cut for about .50 in.
Check angle with protractor
If angle correct, continue cut
Machine to required depth, taking several cuts if necessary

29. Alternate Method Milling an Angular Surface
Check if vertical head is square with table
Clean vise
Lock quill clamp
Set workpiece in vise with layout line parallel to top of vise jaws and about .250 in. above them
Adjust work so cut will start at narrow side of taper and progress into thicker metal

30. Check to see that cut and layout line parallel
Take successive cuts of about .125 to .150 in. or until cut is about .030 in. above layout line
Check to see that cut and layout line parallel
Raise table until cutter just touches layout line
Clamp knee at this setting
Take finishing cut

31. Milling Hardened Steel with PCBN Tools
PCBN blank tools and inserts widely used in general machining and tool and die work
Consistent part accuracy, cool-cutting features, and high productivity
Can be used on abrasive and difficult-to-cut metals (alloy, tool steel hardened above 45 Rc)

32. Factors to Consider Before Using PCBN or Other Cutting Tool
Select milling machine that is in good working order
Know machine's capabilities
Select proper toolholder and tool grade, and follow tool preparation procedures
Calculate proper speed, feed, depth of cut
Follow recommended setup and machining sequence

33. Preparation for PCBN Milling
Interactive Superabrasive Machining Advisor
Software supplied by GE Superabrasives used for selection of PCBN tool and machining conditions
To use effectively must know following:
Material hardness, machine horsepower, maximum spindle speed, maximum table feed, depth of cut and surface finish
Software recommends:
Tool grade, tool edge preparation, tool geometry, surface speed and r/min, feed per tooth and in./min and coolant

34. Machining the Part
For procedure listed in the following slides assume the following:
Piece of alloy steel hardened to Rc
Standard vertical milling machine with 2 HP spindle
2.0 in diameter facemill with R-8 shank, containing single PCBN insert with geometry of CNMA 433
Insert had edge chamfer of 15º x .008 in. with .001 in. hone
Insert grade was BZN® 6000 used without coolant
Depth of cut of .020 in. at 500 sf/min, feed rate .006 in.

35. Machine Setup Set machine spindle to recommended r/min
Set table feed to recommended feed in in./min
Fasten single PCBN insert into proper toolholder
Fasten cutter into machine spindle and lock quill in up position to ensure rigidity
Tighten all table locks except table machining axis

36. Use .010 in. plastic shim to set tool to top of part surface
Move table so cutter clears part and raise knee the thickness of shim plus desired depth of cut
Feed table and machine the part surface
Do NOT traverse back across part until knee lowered or table moved off part to prevent tool chipping
Reposition and take additional passes until part machined to size

37. Producing and Finishing Holes
Location of holes, slots, etc. can be located accurately by using micrometer collars on table feed screws
Holes can be drilled 90º to work surface, or any angle that head can be swiveled
Procedure to Drill Holes at 90º
Mount work in vise, or clamp to table; work must be supported by parallels

38. Mount drill chuck in spindle
Mount center finder in drill chuck
Adjust table until center-punch mark of hole to be drilled is in line with tip of rotating center finder
or Locate center of machine spindle on two adjacent edges of workpiece and move table to hole location using table feed screw micrometer collars
Tighten table and saddle clamps

39. Stop machine and remove center finder
Mount center drill in drill chuck
Extend only .50 in. to prevent breakage
Set spindle speed to ~1000 r/min, and feed center drill with quill handfeed lever until about half of angular portion enters work
Mount drill size required in drill chuck
Set depth stop so that drill just clears bottom of workpiece to prevent drilling into machine table

40. Set machine to proper speed and feed if automatic feed to be used for drilling hole
Apply cutting fluid and use quill handfeed lever, or automatic feed, to drill hole

41. To Drill Angular Holes
Angular holes drilled by swiveling head to required angle and feeding drill into work by using quill handfeed lever
Procedure
Mount work in vise, or clamp it to machine table
Loosen lock nuts and swivel milling head to required angle of hole to be drilled

42. Tighten lock nuts, recheck accuracy of setting
Check angle of head by graduations on housing, or with bevel, or vernier protractor
Tighten lock nuts, recheck accuracy of setting
Mount drill chuck in spindle
Mount center finder in drill chuck
Locate center of spindle as close as possible to where hole is to be drilled
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

43. Lower table so there is enough room between spindle in up position and top of work to mount longest drill required for drilling operation
Lock knee of machine in position and do not move it
Adjust table until center-punch mark of hole to be drilled is in line with tip of rotating center finder OR Locate center of machine spindle on two adjacent edges of workpiece and move table to hole location using table feed screw micrometer collars

44. Tighten table and saddle clamps
Stop machine, raise spindle to top position with quill handfeed lever, and remove center finder
Insert large center drill or spotting tool into drill chuck
Set spindle speed for size of spotting tool to be used
Spot each hole location so top of hole slightly larger than size of hole to be drilled

45. When more than one angular hole must be drilled, wise to record crossfeed and table micrometer collar locations of each hole
Stop machine and remove spotting tool
Insert correct-size drill into drill chuck
Set speed and feed for each hole to be drilled
Drill each hole to required depth
Remove all burrs from hole edges with file and scraper

46. To Ream on a Vertical Mill
Purpose of reaming is to bring drilled or bored hole to size and shape and produce good surface finish in hole
Accuracy affected by speed, feed, and reaming allowance
Speed generally about ½ of drilling speed
Allowance: .250 in for holes up to .500 in in diameter, .030 in. for holes over .500 in.
Two types of reamers: rose (fluted) and precision end-cutting

47. Procedure To Ream on a Vertical Mill
Mount reamer in spindle or drill chuck
Set speed and feed for reaming
Apply cutting fluid as reamer fed steadily into hole with downfeed lever
Stop machine spindle
Remove reamer from hole

48. To Bore on a Vertical Mill
Boring is operation of enlarging and truing drilled or cored hole with single-point cutting tool
Offset boring chuck allows accurate settings
Procedure
Align vertical head square (90º) to table
Set up and align work parallel to table travel

49. Align center of milling machine spindle with reference point or edges of work
Set graduated micrometer dials on crossfeed and table screws to zero
Calculate coordinate location for hole
Move table so center of spindle aligns with hole location required
Lock all table clamps to keep position
Spot hole location with center drill or spotting tool

50. Drill holes under. 500 in. diameter to within. 015 in
Drill holes under .500 in. diameter to within .015 in. of finish size; holes over .500 in. diameter to within .030 in. of size
Mount boring chuck using largest boring bar or tool possible
Rough bore hole to within .005 to .007 in. of finish size
Finish boring hole to required size

51. To Tap a Hole on Vertical Mill
Can be performed either by hand or with use of tapping attachment
Procedure
Mount work in vise, or clamp it to machine table
Mount center drill in drill chuck, adjust machine table until center-punch mark on work aligns with point of center drill

52. Drill hole to correct tap drill size for size of tap to be used
With center drill spot each hole to be tapped to slightly larger than tap diameter
Drill hole to correct tap drill size for size of tap to be used
Mount stub center in drill chuck
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

53. Fasten tap wrench on correct-size tap and place it into hole
Lower spindle using quill handfeed lever until stub center point fits into center hole in end of tap shank
Turn tap wrench clockwise to start tap into hole; at same time, keep stub center in light contact with tap by applying pressure on handfeed lever
Continue to tap hole while keeping tap aligned by applying light pressure on handfeed lever

54. Slots and Keyseats
May be cut in shafts more easily on vertical milling machine, using a two- or three-fluted end mill
Procedure for Cutting
Layout position of keyseat on shaft, and scribe reference lines on end of shaft
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

55. Secure workpiece in vise on parallel
Using layout lines on end of shaft, set up shaft so that keyseat layout is in proper position on top of shaft
Mount a two- or three-fluted end mill of diameter equal to width of keyseat, in milling machine spindle
If two blind ends, two- or three-lip end mill must be used
Center workpiece by carefully touching cutter to one side of shaft
May place piece of thin paper between shaft and cutter

56. Lower table until cutter clears workpiece
Move table over amount equal to half diameter of shaft plus half diameter of cutter plus thickness of paper
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

57. If keyseat being cut has two blind ends, adjust work until end of keyseat aligned with edge of cutter
Feed cutter down (or table up) until cutter just cuts to its full diameter
Adjust dept of cut one-half thickness of key, and machine keyseat to proper length

58. Calculating Depth of Keyseats
If keyseat at end of shaft, proper depth of keyseat checked by measuring diametrically from bottom of keyseat to opposite side of shaft
h = height of the segment above the width of the keyseat
W = width of keyseat
D = diameter of shaft
H = distance from bottom of keyseat to opposite side of shaft
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

59. Woodruff Keys Used when keying shafts and mating parts
Woodruff keyseats can be cut more quickly than square keyseats
Semicircular in shape and can be purchased in standard sizes designated by E numbers
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

60. Woodruff Keyseat Cutters
Have shank diameters of ½ in. for cutters up to 1 ½ in. in diameter
Cutters over 2 in. in diameter mounted on arbor
Size stamped on shank
Last two digits indicate nominal diameter in eighths of inch
Preceding numbers nominal width of cutter in thirty-seconds of an inch
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

61. Procedure to Cut a Woodruff Keyseat
Align spindle of vertical milling machine 90º to table
Lay out position of keyseat
Set shaft in vise of milling machine or on V-blocks
Mount cutter of proper size in spindle

62. Start cutter, touch bottom of cutter to top of workpiece
Set vertical graduated feed collar to zero
Check cutter rotation
Move work clear of cutter
Raise table half diameter of work plus half thickness of cutter
Lock knee at setting
Position center of slot with center of cutter
Lock table in position

63. Touch revolving cutter to work Cut keyseat to proper depth
Set crossfeed screw collar to zero
Cut keyseat to proper depth
Note: Keyseat proportions may be found in any handbook.